Network camera apparatus, network camera server and digital video recorder for preventing forgery and alteration of digital image, and apparatus for authenticating the digital image from said apparatus, and method thereof

摘要

The present invention discloses a network camera apparatus, network camera server and digital video recorder which makes it possible to prevent a digital image from being forged or altered by embedding a watermark into an image signal input through a camera in a real time. Two types of watermark, i.e. a robust watermark for authenticating whether the image is original image or not and a fragile watermark whether the image is forged or altered or where the forgery or alteration of image takes place. An authentication apparatus for authenticating the watermark-embedded image is further disclosed.